Process of preparing a silica-alumina supported group viii metal hydrocracking catalyst

Claim 1

A PROCESS FOR THE PREPARATION OF A SILICA-ALUMINA SUPPORTED GROUP VIII METAL HYDROCRACKING CATALYST WHICH COMPRISES COMMINGLING AN ALKALI METAL SILICATE SOLUTION WITH A SUFFICIENT QUANTITY OF A MINERAL ACID SOLUTION TO FORM AN ACIDIC-SALT-CONTAINING SILICA SOL, FIRST GELLING AND AGING THE RESULTANT SALT-CONTAINING SILICA SOL, FIRST GELLING AND AGING THEN ADDING AN ALALINE REAGENT AND FURTHER AGING THE RESULTANT GEL UNDER BASIS CONDITIONS, COMMINGLING THE RESULTANT AGED GEL WITH AN ALUMINUM SALT SOLUTION, PRECIPITATING A SOLICA-ALUMINA COMPOSITE THEREFROM BY THE ADDITION OF A BASIS PRECIPITANT SUFFICIENT TO RAISE THE PH TO AT LEAST 8, WATER WASHING THE FRESHLY PRECIPITATED, UNDRIED SILICA-ALUMINA COMPOSITE SUFFICIENTLY TO REMOVE FROM ABOUT 10% TO ABOUT 90% BUT NOT ALL OF THE WATER SOLUBLE SALTS THEREFROM, DRYING SAID WATER WASHED SILICA-ALUMINA COMPOSITE AT A TEMPERATURE OF FROM ABOUT 2000F. TO ABOUT 500*F., FURTHER WATER WASHING THE RESULTANT DRIED SILICA-ALUMINA COMPOSITE SUFFICIENTLY TO REMOVE THE REMAINING WATER SOLUBLE SALTS THEREFROM, CALCINING THE THUS PURIFIED SILICA-ALUMINA COMPOSITE AT A TEMPERATURE OF FROM ABOUT 800*F. TO ABOUT 1400*F., AND IMPREGNATING THE CALCINED SILICAALUMINA COMPOSITE WITH A GROUP VIII METAL CATALYTIC COMPONENT.